Peel and quarter the shallots. Clean and trim the mushrooms. Peel, wash and slice carrots. Wash and clean the mangetouts. Wash the meat, dab dry and cut into strips.
Place puff pastry slices next to each other on a floured work surface and allow to thaw. Heat the oil in a frying pan. Fry meat for 5-10 minutes, turning. Add carrots, shallots, mushrooms and mangetouts to the pan and fry for 5 minutes.
Deglaze with white wine and roast stock. Add cream and season with salt and pepper. Add sauce thickener while stirring, let it boil for 1 minute. Put the ragout into a greased casserole dish (1.5 litres capacity).
Cut the puff pastry into strips and spread them over the casserole to form a grid. Mix the egg yolk with 2 tablespoons of water, spread the puff pastry with it. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 20 minutes.